Catalyst for decomposition of hydrocarbons and process

ABSTRACT

1. THE PROCESS OF REACTING HYDROCARBONS TO YIELD HYDROGEN COMPRISING HEATING A C CATALYST CONSISTING OF NICKEL OXIDE SUPPORTED ON A POROUS BASE OF CERAMIC BONDED ZIRCON GRAINS TO A TEMPERATURE OF FROM 1800* TO 2200*F., PASSING SAID HYDROCARBONS OVER SAID CATALSYT, AND RECOVERING THE PRODUCT HYDROGEN.

United States Patent Company, Worcester, Mass. No Drawing. Continuation-impart of fion Ser. No. 44,638, June 8, 1970. This application Mar. 20, 1972, Ser. No. 236,221 I 1 y Int. Cl. C101 1/20 US. Cl. 423-653 a I 1 Claim ABSTRACT OF THE DISCLOSURE A self-bonded or ceramic bonded zircon carrier on which nickel oxide catalyst is deposited is useful inv producing hydrogen by the reaction:

C H XC Y/2 H and producing annealing gas by the reaction:

. at from 1800" F. to 2200 F.

This application is a continuation in part of application Ser. No. 44,638, filed June 8, 1970, now abandoned.

FIELD OF THE INVENTION The invention relates to a catalyst and process for the decomposition of hydrocarbons to produce hydrogen or to produce annealing gas. In the first instance the feed is a hydrocarbon or hydrocarbon mixture such as gasoline thus:

In the second gaseous hydrocarbons are mixed with air to give CO and hydrogen, thus:

BACKGROUND OF THE INVENTION A need for a practical process for producing hydrogen in good yield from hydrocarbons such as gasoline, for use in applications such as portable fuel cells, has not been adequately met by available catalyst systems.

Similarly, a standard catalyst'for producing annealing gas (CO+H is nickel on firebrick. This catalyst is not entirely satisfactory because of its short life due to deactivation and physical disintegration.

U.S. Pat. 3,205,182 teaches that supported nickel catalysts are deactivated when exposed to oxygen due to reaction of the nickel with the support. Contrary to the teachings of that patent which require the use of a second metal oxide we have discovered that nickel oxide on zircon is an effective and stable catalyst for the decomposition of hydrocarbons to yield hydrogen, and for the partial oxidation of hydrocarbons.

SUMMARY OF THE INVENTION The present invention involves the use of a zircon catalyst carrier for a nickel catalyst for both of the above applications. The catalyst system provides good yields of product and is superior in life to other known catalysts for these applications. The carrier material may be zircon or a mixture of zircon and up to 50% by weight of zirconia. The carrier may be self-bonded by sintering a prepared shaped mix at Orton cone 16, or higher, or preferably may be ceramic bonded by standard ceramic bonds of clay or clay and additives such as feldspar. The carrier thus may contain from 0% (for self-bonded) to, say, 20% of a ceramic bond. The metal catalyst is applied to the carrier in the form of an oxide by conventional techniques such abandoned applicaas impregnation from a salt solution, followed by conversion to the oxide by heating. During use there will be at least partial conversion to the elemental metal form.

DESCRIPTION OF SPECIFIC EMBODIMENTS A mix of zircon and ceramic bond was prepared from the following dry ingredients:

Parts by weight Granular Zircon Ball clay 12 Feldspar 7 Bentonite 1 To 100 parts of the above mix were added 14.5 parts of water and 11 parts of the following mix:

Parts by weight 3 Corn flour Grease 4 /2 Rye flour 1 Polystyrene hollow beads (1 mm. diameter) 2 The mix was formed into /2 inch spheres and fired to 1450" C.

The resulting support had the following properties:

Apparent porosity 48.5 Volume percent.

Water adsorption 23.5 percent.

Specific gravity 3.95

Bulk density 2.04 grams/cubic centimeter. Packing density 59.1 pounds/cubic foot.

2.4% nickel by weight.

EXAMPLE 1 A reactor tube 2" in diameter and 1' long was packed with the catalyst described above. The reactor was heated in a gas flame to 18002200 'F. Gasoline was pumped into the reactor at an approximate rate of 15 mL/min. In 3 to 4 minutes the catalyst would be inactivated by carbon deposition. Air was then passed over the catalyst for several minutes to burn the carbon from the catalyst. This cyclic operation was continued for 100 hours.

The gas produced during the cracking cycle was primarily hydrogen. Between and 97 percent of the hydrogen in the gasoline is covered as hydrogen gas in each cycle. The average hydrogen recovery over the 100 hour period was During the hour run the catalyst showed no decline in activity.

The extreme chemical stability of the catalyst is demonstrated by this example. Nickel on alumina catalysts tested in an identical manner were completely deactivated in 3 to 4 hours of operation.

This example demonstrated a process for making hydrogen from liquid hydrocarbons. The hydrogen is uncontaminated by carbon oxides which is often a considerable advantage. One area in which this invention may be very useful is the manufacture of portable hydrogen generators to provide hydrogen fuel to fuel cells. Fuel cells are used to generate electricity in remote or portable installations.

Y EXAMPLE 2 h Approximately 1.4 ft. of the nickel on zircon catalyst was charged into the Inconel' reactor of an annealing gas generator. The reactor was heated by gas flames to '1850" F. Air and methane gas were fed to the reactor in sufiicient quantity to provide-750 s.c.f./h. of product gas (CO+H +N The air was supplied in the ratio of 2.5 volume/volume of CH This air/CH ratio produces about 0.5 Vol. CO in the product gas and an approximate dew point of 25 F.

After 6 months of continuous operation, the catalyst has shown no decline in activity and no physical degradation. The product gas shows an unconverted methane content that variesfrom 0.1 to 0.4 percent.

1 The catalyst ordinarily used in these annealing gas generators is nickel impregnated firebrick. At conditions similar .to those in Example 2,-theselcatalysts normally have a useful life of 3 to 4 months. r

Thus Example 2 demonstrates the usefulness of the nickel-zircon catalyst in the generation of reducing atmosphere (CO-H by the partial combustion of methane. A common problem in annealing plants is the coking of the catalyst. Example 1 shows that the nickel-zircon catalyst can be regenerated many times without losing its activity or physical integrity.

What is claimed is;

1. The process of reacting hydrocarbons .to yield hydrogen-comprising heating a catalyst consisting of nickel oxide supported on a porous base of ceramic bonded zircon grains to a temperature of from 1800 to'2200" F., passing said hydrocarbons over said catalyst, and recovering the product hydrogen.

References Cited UNITED STATES PATENTS 3,256,207 6 /1966 Arnold 423415 X 3,014,787 12/1961 Peet 423651 X 3,314,761 -4/1'967 McCartney et a1. 423 651 CARL F. DEES, Primary Examiner 

1. THE PROCESS OF REACTING HYDROCARBONS TO YIELD HYDROGEN COMPRISING HEATING A C CATALYST CONSISTING OF NICKEL OXIDE SUPPORTED ON A POROUS BASE OF CERAMIC BONDED ZIRCON GRAINS TO A TEMPERATURE OF FROM 1800* TO 2200*F., PASSING SAID HYDROCARBONS OVER SAID CATALSYT, AND RECOVERING THE PRODUCT HYDROGEN. 